[alsa-devel] [PATCH v2] alsactl: Store lockfile in /tmp

[Julian Scheel]

It can not be generally assumed that the directories in which asound.state
resides are writable. Instead using /tmp as location for lock files seems more
reliable.

Signed-off-by: Julian Scheel <julian at jusst.de>
---
 alsactl/alsactl.c |  7 +++++++
 alsactl/alsactl.h |  1 +
 alsactl/lock.c    | 13 ++++++++++---
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/alsactl/alsactl.c b/alsactl/alsactl.c
index 6bc013f..415dfb8 100644
--- a/alsactl/alsactl.c
+++ b/alsactl/alsactl.c
@@ -38,6 +38,9 @@
 #ifndef SYS_PIDFILE
 #define SYS_PIDFILE "/var/run/alsactl.pid"
 #endif
+#ifndef SYS_LOCKPATH
+#define SYS_LOCKPATH "/var/lock"
+#endif
 
 int debugflag = 0;
 int force_restore = 1;
@@ -46,6 +49,7 @@ int do_lock = 0;
 int use_syslog = 0;
 char *command;
 char *statefile = NULL;
+char *lockpath = SYS_LOCKPATH;
 
 #define TITLE	0x0100
 #define HEADER	0x0200
@@ -71,6 +75,7 @@ static struct arg args[] = {
 { HEADER, NULL, "Available state options:" },
 { FILEARG | 'f', "file", "configuration file (default " SYS_ASOUNDRC ")" },
 { 'l', "lock", "use file locking to serialize concurrent access" },
+{ FILEARG | 'D', "lock-dir", "directory to use for lock files (default " SYS_LOCKPATH ")" },
 { 'F', "force", "try to restore the matching controls as much as possible" },
 { 0, NULL, "  (default mode)" },
 { 'g', "ignore", "ignore 'No soundcards found' error" },
@@ -232,6 +237,8 @@ int main(int argc, char *argv[])
 		case 'l':
 			do_lock = 1;
 			break;
+		case 'D':
+			lockpath = optarg;
 		case 'F':
 			force_restore = 1;
 			break;
diff --git a/alsactl/alsactl.h b/alsactl/alsactl.h
index 9109a70..6c6bee5 100644
--- a/alsactl/alsactl.h
+++ b/alsactl/alsactl.h
@@ -5,6 +5,7 @@ extern int do_lock;
 extern int use_syslog;
 extern char *command;
 extern char *statefile;
+extern char *lockpath;
 
 void info_(const char *fcn, long line, const char *fmt, ...);
 void error_(const char *fcn, long line, const char *fmt, ...);
diff --git a/alsactl/lock.c b/alsactl/lock.c
index 587a109..c69e285 100644
--- a/alsactl/lock.c
+++ b/alsactl/lock.c
@@ -36,17 +36,24 @@ static int state_lock_(const char *file, int lock, int timeout)
 	struct flock lck;
 	struct stat st;
 	char lcktxt[12];
+	char *filename;
 	char *nfile;
 
 	if (!do_lock)
 		return 0;
-	nfile = malloc(strlen(file) + 6);
+
+	/* only use the actual filename, not the path */
+	filename = strrchr(file, '/');
+	if (!filename)
+		filename = file;
+
+	nfile = malloc(strlen(lockpath) + strlen(filename) + 7);
 	if (nfile == NULL) {
 		error("No enough memory...");
 		return -ENOMEM;
 	}
-	strcpy(nfile, file);
-	strcat(nfile, ".lock");
+
+	sprintf(nfile, "%s/%s.lock", lockpath, filename);
 	lck.l_type = lock ? F_WRLCK : F_UNLCK;
 	lck.l_whence = SEEK_SET;
 	lck.l_start = 0;
-- 
1.9.2